Timeline of discovery of Solar System planets and their moons
The timeline of discovery of Solar System planets and their natural satellites charts the progress of the discovery of new bodies over history. Each object is listed in chronological order of its discovery (multiple dates occur when the moments of imaging, observation, and publication differ), identified through its various designations (including temporary and permanent schemes), and the discoverer(s) listed. Historically the naming of moons did not always match the times of their discovery. Traditionally, the discoverer enjoys the privilege of naming the new object; however, some neglected to do so (E. E. Barnard stated he would "defer any suggestions as to a name" Amalthea "until a later paper" but never got around to picking one from the numerous suggestions he received) or actively declined (S. B. Nicholson stated "Many have asked what the new satellites" and Carme "are to be named. They will be known only by the numbers X and XI, written in Roman numerals, and usually prefixed by the letter J to identify them with Jupiter." ). The issue arose nearly as soon as planetary satellites were discovered: Galileo referred to the four main satellites of Jupiter using numbers while the names suggested by his rival Simon Marius gradually gained universal acceptance. The International Astronomical Union (IAU) eventually started cleaning up the naming business in the late 1970s. Key In the following tables, planetary satellites are indicated in bold type (e.g. Moon) while planets and dwarf planets, which directly circle the Sun, are in italic type (e.g. Earth). The tables are sorted by publication/announcement date. Dates are annotated with the following symbols: * i: for date of first imaging (photography, etc.); * o: for date of first human visual observation, either through telescope or on photographic plate (the true discovery moment); * p: for date of announcement or publication. In a few cases, the date is uncertain and is then marked "(?)". * Note: Moons marked by an asterisk (*) had complicated discoveries. Some took years to be confirmed, and in several cases were actually lost and rediscovered. Others were found in Voyager photographs years after they were taken. ;Color legend The planets and their natural satellites are marked in the following colors: ;Planets ;Dwarf planets ;Designations * Other designations are synonyms or periphrases sometimes encountered for the object. * Permanent designations (of planetary satellites) are explained here. * Temporary designations are explained here. Prehistory |- | bgcolor="#FFE8E8" | Jupiter | bgcolor="Black" | || bgcolor="#FFE8E8" | 5th Planet |- | bgcolor="#FFFFCC" | Saturn | bgcolor="Black" | || bgcolor="#FFFFCC" | 6th Planet |} 17th century 18th century 19th century Early 20th century (1901–1950) Late 20th century (1951–2000) 21st century 2000s 2010s See also * Timeline of Solar System astronomy * Timeline of Solar System exploration * Solar System References External links * City of Hudson's Natural Satellite Page * Scott Sheppard's Giant Planet Satellite Page * JPL Natural Satellite Discovery Data * James L. Hilton, When did the asteroids become minor planets? Category:Moons Category:Discovery and exploration of the Solar System Category:Lists of Solar System objects Solar system, planets, natural satellites, timeline of Solar system objects